Conventional optical microscopes are equipped with viewing optics arranged on an arm and a sample stage positioned below the sample stage within a focal range of the optics. A sample substrate, i.e. a microscope slide containing the sample to be imaged, is positioned on the sample stage at the optical axis of the viewing optics.
Scanning optical microscopes are used e.g. in microscopy of biological samples and material diagnostics. They typically comprise a specially designed sample stage with integral members for holding a slide and moving the slide perpendicular to the optical axis of the viewing optics (say in X and Y dimensions) so that different parts of the sample can easily be viewed. There may be also an electrical drive for actuation of the movement in an automated fashion.
There are also sample stage assemblies for converting conventional sample stages into X-Y-movable stages. For example WO 2005/101088 discloses a stage assembly mountable on an optical microscope for orienting a sample into a desired focal position includes an X-axis plate operable for rectilinear shifting in the X-axis direction and a Y-axis plate mounted on the X-axis plate operable for rectilinear translation in the Y-axis direction. A Z-axis plate is mounted on the XY plate assembly for carrying a sample to be investigated and a piezoelectric actuator mechanism is interposed between the XY plate assembly and the Z-axis plate operable for rectilinear translation of the Z-axis plate.
In the patent literature, further art is represented by WO 2011/138603, WO 2013/138911, US 2010/0073672, US 2008/0266440, US 2011/0089771, US 2012/0147461 and US 2002/0101654.
In addition, there are separate devices that can be placed on sample stages, such as PInano® “XY(Z) Piezo System P-545.xR7”-series nanopositioning device, designed for superresolution microscopy. The device comprises a shallow but large body with a slide-receiving aperture in the middle and is capable of moving the slide at maximum 0.2 mm in each dimension. Due to its design, the device requires, however a huge amount of flat space on a sample stage compared with the area of the slide, and is therefore not suited for the majority of existing microscopes.
In summary, the existing solutions for automatically moving samples to be imaged require special microscopes with custom sample stages, extensive modifications to ordinary stages or at least large flat sample stages for being able to accommodate the slide moving device.
Thus, there exists a need for improved solutions allowing moving of samples in microscopes with laterally stationary sample stages.